The Plumber's Choice Universal Fit for 3 in. and 4 in. Waste Lines Elastic Waxless Toilet Ring Seals Bowl 1006US - The Home Depot
Seal gasket toilet bowl rubber ring for toilet, View toilet bowl rubber ring, Meizhi Product Details from Chaoan Meizhi Ceramics Co., Limited on Alibaba.com
LASCO 04-3328 Cushion Ring for Wall Hung Toilet, 6 3/4-OD x 3 1/2-ID x 9/16-Inch Thick, Sponge Rubber - - Amazon.com
Tyleen rubber ring in diverse variaties verkrijgbaar : Handelsonderneming Smolders B.V.